The NotificationService has to do quite a lot of work to calculate the
recipients for an email. Where possible, we should try to avoid doing this in an
HTTP request, because the mail are sent by Sidekiq anyway, so there's no need to
schedule those emails immediately.
This commit creates a generic Sidekiq worker that uses Global ID to serialise
and deserialise its arguments, then forwards them to the NotificationService.
The NotificationService gains an `#async` method, so you can replace:
notification_service.new_issue(issue, current_user)
With:
notification_service.async.new_issue(issue, current_user)
And have everything else work as normal, except that calculating the recipients
will be done by Sidekiq, which will then schedule further Sidekiq jobs to send
each email.
Having two states that essentially mean the same thing is very much like
having a boolean "true" and boolean "mostly-true": it's rather silly.
This commit merges the "reopened" state into the "opened" state while
taking care of system notes still showing messages along the lines of
"Alice reopened this issue".
A big benefit from having only two states (opened and closed) is that
indexing and querying becomes simpler and more performant. For example,
to get all the opened queries we no longer have to query both states:
SELECT *
FROM issues
WHERE project_id = 2
AND state IN ('opened', 'reopened');
Instead we can query a single state directly, which can be much faster:
SELECT *
FROM issues
WHERE project_id = 2
AND state = 'opened';
Further, only having two states makes indexing easier as we will only
ever filter (and thus scan an index) using a single value. Partial
indexes could help but aren't supported on MySQL, complicating the
development process and not being helpful for MySQL.
When an issuable's state changes, or one is created, we should clear the cache
counts for a user's assigned issuables, and also the project-wide caches for
this user type.
